#!/usr/bin/env bash
help() {
    blink=$'\e[1;31m' reset=$'\e[0m'
cat <<EOF
This script can only be used as a userscript for qutebrowser
2015, Thorsten Wißmann <edu _at_ thorsten-wissmann _dot_ de>
In case of questions or suggestions, do not hesitate to send me an E-Mail or to
directly ask me via IRC (nickname thorsten\`) in #qutebrowser on freenode.

  $blink!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!$reset
  WARNING: the passwords are stored in qutebrowser's
           debug log reachable via the url qute://log
  $blink!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!$reset

Usage: run as a userscript form qutebrowser, e.g.:
  spawn --userscript ~/.config/qutebrowser/password_fill

Pass backend: (see also passwordstore.org)
  This script expects pass to store the credentials of each page in an extra
  file, where the filename (or filepath) contains the domain of the respective
  page. The first line of the file must contain the password, the login name
  must be contained in a later line beginning with "user:", "login:", or
  "username:" (configurable by the user_pattern variable).

Behavior:
  It will try to find a username/password entry in the configured backend
  (currently only pass) for the current website and will load that pair of
  username and password to any form on the current page that has some password
  entry field. If multiple entries are found, a zenity menu is offered.

  If no entry is found, then it crops subdomains from the url if at least one
  entry is found in the backend. (In that case, it always shows a menu)

Configuration:
  This script loads the bash script ~/.config/qutebrowser/password_fill_rc (if
  it exists), so you can change any configuration variable and overwrite any
  function you like.

EOF
}

set -o errexit
set -o pipefail
shopt -s nocasematch # make regexp matching in bash case insensitive

if [ -z "$QUTE_FIFO" ] ; then
    help
    exit
fi

error() {
    local msg="$*"
    echo "message-error '${msg//\'/\\\'}'" >> "$QUTE_FIFO"
}
msg() {
    local msg="$*"
    echo "message-info '${msg//\'/\\\'}'" >> "$QUTE_FIFO"
}
die() {
    error "$*"
    exit 0
}

javascript_escape() {
    # print the first argument in an escaped way, such that it can safely
    # be used within javascripts double quotes
    # shellcheck disable=SC2001
    sed "s,[\\\\'\"],\\\\&,g" <<< "$1"
}

# ======================================================= #
# CONFIGURATION
# ======================================================= #
# The configuration file is per default located in
# ~/.config/qutebrowser/password_fill_rc and is a bash script that is loaded
# later in the present script. So basically you can replace all of the
# following definitions and make them fit your needs.

# The following simplifies a URL to the domain (e.g. "wiki.qutebrowser.org")
# which is later used to search the correct entries in the password backend. If
# you e.g. don't want the "www." to be removed or if you want to distinguish
# between different paths on the same domain.

simplify_url() {
    simple_url="${1##*://}" # remove protocol specification
    simple_url="${simple_url%%\?*}" # remove GET parameters
    simple_url="${simple_url%%/*}" # remove directory path
    simple_url="${simple_url%:*}" # remove port
    simple_url="${simple_url##www.}" # remove www. subdomain
}

# no_entries_found() is called if the first query_entries() call did not find
# any matching entries. Multiple implementations are possible:
# The easiest behavior is to quit:
#no_entries_found() {
#    if [ 0 -eq "${#files[@]}" ] ; then
#        die "No entry found for »$simple_url«"
#    fi
#}
# But you could also fill the files array with all entries from your pass db
# if the first db query did not find anything
# no_entries_found() {
#     if [ 0 -eq "${#files[@]}" ] ; then
#         query_entries ""
#         if [ 0 -eq "${#files[@]}" ] ; then
#             die "No entry found for »$simple_url«"
#         fi
#     fi
# }

# Another behavior is to drop another level of subdomains until search hits
# are found:
no_entries_found() {
    while [ 0 -eq "${#files[@]}" ] && [ -n "$simple_url" ]; do
        # shellcheck disable=SC2001
        shorter_simple_url=$(sed 's,^[^.]*\.,,' <<< "$simple_url")
        if [ "$shorter_simple_url" = "$simple_url" ] ; then
            # if no dot, then even remove the top level domain
            simple_url=""
            query_entries "$simple_url"
            break
        fi
        simple_url="$shorter_simple_url"
        query_entries "$simple_url"
        #die "No entry found for »$simple_url«"
        # enforce menu if we do "fuzzy" matching
        menu_if_one_entry=1
    done
    if [ 0 -eq "${#files[@]}" ] ; then
        die "No entry found for »$simple_url«"
    fi
}

# Backend implementations tell, how the actual password store is accessed.
# Right now, there is only one fully functional password backend, namely for
# the program "pass".
# A password backend consists of three actions:
#  - init() initializes backend-specific things and does sanity checks.
#  - query_entries() is called with a simplified url and is expected to fill
#    the bash array $files with the names of matching password entries. There
#    are no requirements how these names should look like.
#  - open_entry() is called with some specific entry of the $files array and is
#    expected to write the username of that entry to the $username variable and
#    the corresponding password to $password

reset_backend() {
    init() { true ; }
    query_entries() { true ; }
    open_entry() { true ; }
}

# choose_entry() is expected to choose one entry from the array $files and
# write it to the variable $file.
choose_entry() {
    choose_entry_zenity
}

# The default implementation chooses a random entry from the array. So if there
# are multiple matching entries, multiple calls to this userscript will
# eventually pick the "correct" entry. I.e. if this userscript is bound to
# "zl", the user has to press "zl" until the correct username shows up in the
# login form.
choose_entry_random() {
    local nr=${#files[@]}
    file="${files[$((RANDOM % nr))]}"
    # Warn user, that there might be other matching password entries
    if [ "$nr" -gt 1 ] ; then
        msg "Picked $file out of $nr entries: ${files[*]}"
    fi
}

# another implementation would be to ask the user via some menu (like rofi or
# dmenu or zenity or even qutebrowser completion in future?) which entry to
# pick
MENU_COMMAND=( head -n 1 )
# whether to show the menu if there is only one entry in it
menu_if_one_entry=0
choose_entry_menu() {
    local nr=${#files[@]}
    if [ "$nr" -eq 1 ] && ! ((menu_if_one_entry)) ; then
        file="${files[0]}"
    else
        file=$( printf '%s\n' "${files[@]}" | "${MENU_COMMAND[@]}" )
    fi
}

choose_entry_rofi() {
    MENU_COMMAND=( rofi -p "qutebrowser> " -dmenu
                        -mesg $'Pick a password entry for <b>'"${QUTE_URL//&/&amp;}"'</b>' )
    choose_entry_menu || true
}

choose_entry_zenity() {
    MENU_COMMAND=( zenity --list --title "qutebrowser password fill"
                          --text "Pick the password entry:"
                          --column "Name" )
    choose_entry_menu || true
}

choose_entry_zenity_radio() {
    zenity_helper() {
        awk '{ print $0 ; print $0 }'                   \
        | zenity --list --radiolist                     \
                 --title "qutebrowser password fill"    \
                 --text "Pick the password entry:"      \
                 --column " " --column "Name"
    }
    MENU_COMMAND=( zenity_helper )
    choose_entry_menu || true
}

# =======================================================
# backend: PASS

# configuration options:
match_filename=1 # whether allowing entry match by filepath
match_line=0     # whether allowing entry match by URL-Pattern in file
                 # Note: match_line=1 gets very slow, even for small password stores!
match_line_pattern='^url: .*' # applied using grep -iE
user_pattern='^(user|username|login): '

GPG_OPTS=( "--quiet" "--yes" "--compress-algo=none" "--no-encrypt-to" )
GPG="gpg"
export GPG_TTY="${GPG_TTY:-$(tty 2>/dev/null)}"
command -v gpg2 &>/dev/null && GPG="gpg2"
[[ -n $GPG_AGENT_INFO || $GPG == "gpg2" ]] && GPG_OPTS+=( "--batch" "--use-agent" )

pass_backend() {
    init() {
        PREFIX="${PASSWORD_STORE_DIR:-$HOME/.password-store}"
        if ! [ -d "$PREFIX" ] ; then
            die "Can not open password store dir »$PREFIX«"
        fi
    }
    query_entries() {
        local url="$1"

        if ((match_line)) ; then
            # add entries with matching URL-tag
            while read -r -d "" passfile ; do
                if $GPG "${GPG_OPTS[@]}" -d "$passfile" \
                     | grep --max-count=1 -iE "${match_line_pattern}${url}" > /dev/null
                then
                    passfile="${passfile#$PREFIX}"
                    passfile="${passfile#/}"
                    files+=( "${passfile%.gpg}" )
                fi
            done < <(find -L "$PREFIX" -iname '*.gpg' -print0)
        fi
        if ((match_filename)) ; then
            # add entries with matching filepath
            while read -r passfile ; do
                passfile="${passfile#$PREFIX}"
                passfile="${passfile#/}"
                files+=( "${passfile%.gpg}" )
            done < <(find -L "$PREFIX" -iname '*.gpg' | grep "$url")
        fi
    }
    open_entry() {
        local path="$PREFIX/${1}.gpg"
        password=""
        local firstline=1
        while read -r line ; do
            if ((firstline)) ; then
                password="$line"
                firstline=0
            else
                if [[ $line =~ $user_pattern ]] ; then
                    # remove the matching prefix "user: " from the beginning of the line
                    username=${line#${BASH_REMATCH[0]}}
                    break
                fi
            fi
        done < <($GPG "${GPG_OPTS[@]}" -d "$path" | awk 1 )
    }
}
# =======================================================

# =======================================================
# backend: secret
secret_backend() {
    init() {
        return
    }
    query_entries() {
        local domain="$1"
        while read -r line ; do
            if [[ "$line" == "attribute.username = "* ]] ; then
                files+=("$domain ${line:21}")
            fi
        done < <( secret-tool search --unlock --all domain "$domain" 2>&1 )
    }
    open_entry() {
        local domain="${1%% *}"
        username="${1#* }"
        password=$(secret-tool lookup domain "$domain" username "$username")
    }
}
# =======================================================

# load some sane default backend
reset_backend
pass_backend
# load configuration
QUTE_CONFIG_DIR=${QUTE_CONFIG_DIR:-${XDG_CONFIG_HOME:-$HOME/.config}/qutebrowser/}
PWFILL_CONFIG=${PWFILL_CONFIG:-${QUTE_CONFIG_DIR}/password_fill_rc}
if [ -f "$PWFILL_CONFIG" ] ; then
    # shellcheck source=/dev/null
    source "$PWFILL_CONFIG"
fi
init

simplify_url "$QUTE_URL"
query_entries "${simple_url}"
no_entries_found
# remove duplicates
mapfile -t files < <(printf '%s\n' "${files[@]}" | sort | uniq )
choose_entry
if [ -z "$file" ] ; then
    # choose_entry didn't want any of these entries
    exit 0
fi
open_entry "$file"
#username="$(date)"
#password="XYZ"
#msg "$username, ${#password}"

[ -n "$username" ] || die "Username not set in entry $file"
[ -n "$password" ] || die "Password not set in entry $file"

js() {
cat <<EOF
    function isVisible(elem) {
        var style = elem.ownerDocument.defaultView.getComputedStyle(elem, null);

        if (style.getPropertyValue("visibility") !== "visible" ||
            style.getPropertyValue("display") === "none" ||
            style.getPropertyValue("opacity") === "0") {
            return false;
        }

        return elem.offsetWidth > 0 && elem.offsetHeight > 0;
    };
    function hasPasswordField(form) {
        var inputs = form.getElementsByTagName("input");
        for (var j = 0; j < inputs.length; j++) {
            var input = inputs[j];
            if (input.type == "password") {
                return true;
            }
        }
        return false;
    };
    function loadData2Form (form) {
        var inputs = form.getElementsByTagName("input");
        for (var j = 0; j < inputs.length; j++) {
            var input = inputs[j];
            if (isVisible(input) && (input.type == "text" || input.type == "email")) {
                input.focus();
                input.value = "$(javascript_escape "${username}")";
                input.dispatchEvent(new Event('change'));
                input.blur();
            }
            if (input.type == "password") {
                input.focus();
                input.value = "$(javascript_escape "${password}")";
                input.dispatchEvent(new Event('change'));
                input.blur();
            }
        }
    };

    var forms = document.getElementsByTagName("form");
    for (i = 0; i < forms.length; i++) {
        if (hasPasswordField(forms[i])) {
            loadData2Form(forms[i]);
        }
    }
EOF
}

printjs() {
    js | sed 's,//.*$,,' | tr '\n' ' '
}
echo "jseval -q $(printjs)" >> "$QUTE_FIFO"
